The invention relates to the grinding (or xe2x80x9csharpeningxe2x80x9d) of card clothings, in particular but not exclusively of card clothings of flats for a revolving flat card. The invention is suitable for the installation of a grinding device (sharpening device) in the card, but is not limited to this way of application and could, therefore, be applied in a device which, if required, can be attached to a card and which can be carried from one card to another card. However, this also sets no limit, the invention could also be applied in a device which is only engaged during the non-operative (not producing) period of a card.
The invention relates to the grinding (or xe2x80x98sharpeningxe2x80x99) of card clothings, in particular but not exclusively of card clothings of flats for a revolving flat card. The invention is suitable for the installation of a grinding device (sharpening device) in the card, but is not limited to this way of application and could, therefore, be applied in a device which, if required, can be attached to a card and which can be carried from one card to another card. However, this also sets no limit, the invention could also be applied in a device which is only engaged during the non-operative (not producing) period of a card.
EP-A-800 895 (corresponds to U.S. Pat. No. 6,129,614) describes a sharpening or grinding device which can be used for grinding of card clothings of flats. With the present invention the concepts of the earlier application are further improved.
According to the earlier application (the earlier invention, respectively) a grinding device comprises a number of single grinding elements, which enter between the points of the card clothing to be ground, thereby brushing across the head portions of the points and thus grinding them. The grinding elements are preferably elastic and bendable.
The grinding elements can be arranged in such a way that during operation they are distributed across the operating width of the card. For this purpose they can be carried by an oblong support, for instance in such a way that each grinding element on one of its ends is fastened onto the support and from where it protrudes laterally. During operation the support can be mounted on the card frame by means of a holder in an approximately predetermined relation to the revolving flat unit, for instance in such a way that the flats are being ground during their xe2x80x98return motionxe2x80x99.
Together, the grinding elements, the support and the holder can form a device which is installed within the card, for instance in such a way that the device is put into operation with the card itself. For this the card can comprise a drive or control means for the grinding device. However, the device can be laid out in such a way that it can be mounted onto the card, it could for instance comprise an own drive or an own control means.
The present invention
According to a first aspect of the present invention a grinding device for card flats, in particular a grinding device according to the earlier invention, is further being characterized, in that it is being provided with a means (preferably a suction means) to remove grinding particles that develop during grinding.
According to a second aspect of the present invention a grinding device according to the previous invention or a device according to the first aspect of the present invention is being further characterised, in that it is arranged in such a way in relation to the card clothing support (for instance a revolving flat unit) in that basically a predetermined engagement depth of the grinding elements into the card clothing results.
The predetermined engagement depth preferably results by presenting of the card clothing support (a flat rod) to the grinding unit, whereat the presenting of the device to the card clothing support is not excluded. For this purpose a controllable presenting device can be furnished.
The arrangement can be chosen in such a way that a change of the engagement depth due to wear of the grinding element can at least partially be compensated, for instance by an appropriate adjustment of the presenting movement.
According to a third aspect of the present invention a grinding device according to the previous invention or according to the first and/or second aspect of the present invention is being further characterised, in that it is being put into a non continuous but controlled discontinuous (intermittent) operation, whereat the expected (effective) operating period can represent less than 5% (possible less than 1%) of the working life of the card.
Exemplified embodiments of the invention are being described hereafter in detail according to the figures of the drawing.
Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.